digitalmars.D.bugs - sort bug: Goes outside of limits of array

dmd v0.100, Fedora Core 1 Linux.
I was getting some segfaults while sorting arrays of real's. So I
implemented by own copy of the comparison function for real's and found
that this eventually gets called where one of the things being compared
is outside of the limits of the array.
I get assert failure on the 4th assertion. Here's the call stack on
that assert, as reported by gdb: